Bit of mistletoe (5)
I believe the answer is:
sprig
'bit of mistletoe' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for sprig that I've seen before include "related to Spike and Brad" , "Purloined" , "Tree shoot; headless nail" , "A tack; a little shoot" , "Small spray of leaves or flowers" .)